This invention relates to laser devices and particularly, although not exclusively, to those which use as lasing media materials which are normally solid or liquid at room temperature and which lase in the gas or vapour phase.
Such a lasing material can be a metal which is heated to the vapour phase in the discharge chamber but which can form pools of molten metal on the bottom of the discharge chamber. If it is required in operation to move the laser device or to operate the device with the discharge chamber tilted, the molten metal will be dislodged and will migrate about or collect at one end of the discharge chamber. Some laser devices which use metal vapours are provided with wicks, usually made of metal mesh, to encourage molten metal to wick back to the discharge area. Such wicks can have a large cross-section and will cause significant obstruction of the laser beam. Also, in certain circumstances, the liquid will not "wet" the wick material and, in any case, when tilted, molten metal can run out of a wick.
The present invention provides a design which is capable of lasing using a metal in the vapour phase and in which lasing can be satisfactorily carried out whilst the laser device is tilted or, indeed, whilst it is moved about.